Can Vaping Cause a Heart Arrhythmia?

Vaping can trigger heart arrhythmias, and the evidence stretches from lab models all the way to large clinical datasets. A study of adolescents and young adults found that those who vaped had roughly twice the risk of developing heart rhythm abnormalities compared with non-vapers. What makes the picture more unsettling is that the risk does not come from nicotine alone: the solvents, flavorings, and even the cooling agents in e-liquids each appear to disturb the heart’s electrical system through distinct pathways.

What Large-Scale Studies Show

The strongest human evidence comes from a study published in the Journal of Pediatrics, which examined adolescents and young adults. Those who vaped had 82 percent greater odds of being diagnosed with a heart rhythm abnormality compared with those who did not vape, and the hazard of developing such abnormalities over time was approximately double.¹ A separate systematic review and meta-analysis that pooled results from multiple studies reached a similar conclusion: e-cigarette users face increased risks of arrhythmias and heart attack compared with non-smokers, driven by the constituents of aerosolized e-liquid, including nicotine and flavorings.²

Electrocardiogram studies add another layer. Chronic e-cigarette users show prolonged QT and QTc intervals and prolonged ventricular repolarization indices compared with non-smokers of the same age and sex. These measurements reflect how long the heart’s ventricles take to electrically “reset” after each beat. When that reset is delayed, the heart becomes more vulnerable to dangerous rhythm disturbances.³

How Nicotine Disrupts the Heart’s Electrical Signals

Nicotine is the best-known culprit, and its effects on heart rhythm are not subtle. When someone vapes a nicotine-containing e-cigarette, the nervous system shifts toward what researchers describe as sympathetic predominance. In practical terms, that means the “accelerator” side of the nervous system takes over from the “brake” side. A controlled experiment exposing participants to e-cigarettes with nicotine, without nicotine, and a sham device found that only the nicotine-containing e-cigarette produced a marked shift in this balance.⁴ This matters because sympathetic overdrive is one of the most reliable triggers for arrhythmia in people who are already susceptible.

At the cellular level, nicotine can provoke both ventricular and atrial arrhythmias. The mechanism involves nicotine and the stress hormones it triggers interacting with potassium channels in cardiac cells. These channels control the flow of charged particles that set the timing of each heartbeat, so disrupting them can make the heart fire too early, too late, or in a chaotic pattern. Beyond acute electrical interference, nicotine also appears to promote structural changes in the atria over time by altering the expression of certain growth-regulating molecules, which could make atrial fibrillation more likely with chronic use.⁵

The Solvents Are Not Innocent Bystanders

Many vapers assume that if they reduce nicotine concentration, or even use zero-nicotine liquid, they are in the clear. The research tells a different story. E-cigarette liquid is typically a blend of propylene glycol and vegetable glycerin. When heated and inhaled as aerosol, these solvents produce their own cardiac effects. A mouse study found that aerosols from propylene glycol and vegetable glycerin alone, with no nicotine or flavoring, induced bradycardia, bradyarrhythmias, and elevations in heart rate variability during exposure. Propylene glycol aerosol and menthol-flavored aerosol also increased ventricular premature beats, the kind of extra heartbeats that can cascade into more dangerous rhythms.⁶

One reason the solvents are problematic is that heating them generates acrolein, an aldehyde that is also present in traditional cigarette smoke. Acrolein activates a receptor called TRPA1, which in turn pushes the nervous system toward sympathetic activation and autonomic imbalance, a pathway to arrhythmia that operates independently of nicotine.⁵ In other words, even the supposedly “harmless” base of the liquid can generate a compound with direct cardiac effects once it hits the heating element.

Flavorings and Cooling Agents

The flavoring landscape of e-cigarettes is vast, and the cardiac research is starting to catch up. Menthol stands out. In mouse studies, menthol-flavored aerosol uniquely altered atrial and atrioventricular conduction, changes not seen with other flavors. It also increased ventricular premature beats in male mice.⁶ These effects appear to be specific to menthol rather than a generic response to any flavoring.

Vanillin, used in vanilla-flavored e-liquids, acts through a different mechanism. It reduces the activity of a particular potassium channel that is critical for maintaining normal heart rhythm. When this channel is impaired, the electrical recovery phase of the heartbeat is prolonged, creating a window where dangerous arrhythmias can take hold.⁷ A separate study found that inhalation of vanilla-flavored e-vapor increased the duration of induced ventricular tachycardia in normal mice, and that the damage was mediated by oxidative stress: when an antioxidant was given beforehand, the harmful reactive oxygen species were neutralized and the arrhythmia effect was prevented.⁸

Cooling agents are another underappreciated concern. Many modern e-liquids use synthetic coolants such as WS-3 and WS-23 to create a cooling throat hit without actual menthol. A recent study found that all coolants worsened the autonomic imbalance caused by e-cigarette aerosol, but the synthetic coolants WS-3 and WS-23 specifically amplified the production of ventricular premature beats. The ventricular arrhythmias correlated with both sympathetic dominance and transient delays in ventricular repolarization, with the strongest correlation seen for WS-23.⁹ This finding is striking because coolants are not regulated the way nicotine or even flavorings are, and many users have no idea they are present in their e-liquid.

Animal Studies and the Severity of the Effects

Much of the mechanistic evidence comes from animal research, which allows scientists to control exposures and measure outcomes impossible to ethically test in humans. One study exposed rats to aerosol from JUUL pods and compared the results to conventional cigarettes, heated tobacco, and marijuana. The rates at which researchers could provoke ventricular tachycardia in the heart were zero percent in clean-air controls, about 63 percent with conventional cigarettes, and roughly 71 percent with JUUL aerosol.¹⁰ That is not a reassuring comparison. When exposed over longer periods, rats in all smoke or aerosol groups developed severe fibrosis (scarring of heart tissue), decreased microvessel density, and greater sympathetic nerve growth in the heart. These structural changes create a substrate for chronic arrhythmia long after any single puff has left the body.¹⁰

A recent review summarized the full catalog of e-cigarette ingredients known to impair the heart’s electrical function: nicotine, aldehydes, flavorants, polycyclic aromatic hydrocarbons, metals, and carbon monoxide can all independently interfere with cardiac rhythm.¹¹ The picture that emerges from the preclinical literature is not one of a single toxin doing one thing; it is a soup of compounds hitting the heart’s electrical system through multiple overlapping pathways.

How Vaping Compares to Cigarettes

A common assumption is that because vaping exposes you to fewer combustion byproducts, its cardiac effects must be much milder than those of traditional cigarettes. The ECG data from human studies does not strongly support that assumption for arrhythmia risk specifically. Chronic e-cigarette users showed prolonged QT and QTc intervals and prolonged ventricular repolarization indices at levels comparable to conventional smokers, and both groups differed from non-smokers by a statistically significant margin.³

In the rat study that tested ventricular tachycardia inducibility, JUUL aerosol actually produced a numerically higher rate than conventional cigarettes, though both were far above the zero-percent baseline of clean air.¹⁰ This does not mean that vaping is worse than smoking overall for the cardiovascular system. Combustible cigarettes deliver a much broader range of toxins with well-established links to atherosclerosis, chronic lung disease, and cancer. But the arrhythmia slice of the risk pie may not be as reduced by switching to vaping as people expect, partly because nicotine itself is a powerful arrhythmia trigger and modern pod-style devices deliver it in large quantities.

High-concentration nicotine devices and the shift toward nicotine salt formulations in recent years are relevant here. Nicotine salts allow smoother inhalation at concentrations that would be harsh with freebase nicotine, meaning users can comfortably take in substantially more nicotine per puff. Because nicotine’s arrhythmogenic effects are dose-dependent, higher delivery may translate directly into greater cardiac risk, especially for the heart’s rhythm.

Why Young People May Be Especially Vulnerable

The adolescent and young adult population is where the epidemiological signal is strongest. The study showing roughly doubled hazard for heart rhythm abnormalities specifically enrolled this age group, and the effect size was large enough to be unmistakable.¹ Several factors may contribute to this. Young hearts are still maturing, and the autonomic nervous system is not fully calibrated until the mid-twenties. Exposing that developing system to repeated sympathetic surges from nicotine could have outsized effects compared with the same exposure in a fully mature adult.

There is also the question of undiagnosed cardiac conditions. A case report described a teenager who suffered cardiac arrest at school after vaping. He was later found to have a congenital anomaly of a coronary artery that had never been detected. The investigators concluded that the sympathetic surge and arrhythmogenic effects of high-dose nicotine from vaping likely precipitated his cardiovascular collapse.¹² A single case report cannot prove causation, but it illustrates a realistic scenario: young people who vape heavily may not know they have an underlying cardiac vulnerability that nicotine can unmask. Unlike older adults, who may have had ECGs or stress tests at some point, teenagers typically have not been screened for subtle heart conditions.

Sex Differences in Arrhythmia Response

The animal research has consistently flagged a sex difference. In the mouse study using e-cigarette solvent aerosols, the cardiac effects during and after exposure were slighter in female mice than in males. Female mice exposed to menthol-flavored aerosol showed a similar trend toward increased ventricular premature beats, but the increase did not reach statistical significance as it did in males.⁶ Whether this sex difference holds up in humans is not yet clear, but estrogen has long been known to influence cardiac repolarization and autonomic tone, so a biological basis for the difference is plausible. For now, neither sex should consider themselves safe from the arrhythmic effects of vaping, but the research community is actively studying whether women might have a somewhat different risk profile.

Cannabis Vaping and the Heart

Vaping cannabis has become common, and the arrhythmia risk does not disappear when you swap nicotine for THC. Cannabis consumption has been independently linked to arrhythmias including ventricular tachycardia and, in rare cases, sudden cardiac death.¹³ In the same rat study discussed earlier, marijuana aerosol produced a ventricular tachycardia inducibility rate of 75 percent, actually the highest of any product tested, above both JUUL and conventional cigarettes.¹⁰ Plant-based marijuana (not vaped through an e-cigarette device) had a lower rate, suggesting something about the device and delivery method itself may amplify the cardiac risk.

People who vape both nicotine and cannabis are layering multiple independent arrhythmia triggers. Nicotine ramps up sympathetic tone, THC has its own effects on heart rate and vascular tone, and both are being delivered through heated aerosols that carry solvents and flavorings with their own cardiac toxicity. The combination has not been well studied in humans specifically, but the animal data suggest that the risks are at least additive and possibly synergistic. If you have a known heart condition or a family history of arrhythmia, dual use is a particularly bad idea.

What Remains Uncertain

The evidence is strong enough to say that vaping poses a real arrhythmia risk, but important gaps remain. Nearly all of the mechanistic data comes from animal studies, and the doses and exposure patterns do not always mirror how a person actually vapes throughout the day. The large human studies are observational, meaning they identify associations but cannot fully rule out other explanations. And the e-cigarette market changes faster than the science can keep up: new devices, new e-liquid formulations, new flavorings, and new delivery technologies mean that a study published today may be testing a product that is already being replaced on shelves.

Reversibility is another open question. Whether the ECG changes and autonomic imbalance seen in chronic vapers fully resolve after quitting is not well characterized. The structural remodeling observed in animal studies, including cardiac fibrosis and changes in nerve growth, would be expected to persist at least partially. For people who have vaped heavily for years, the practical question of whether stopping will “undo” the cardiac damage remains unanswered by the current literature.

1
PubMed. Increased Risk of Heart Rhythm Abnormalities in Adolescents and Young Adults Who Vape
2
PubMed. Comparing E-Cigarettes and Traditional Cigarettes in Relation to Myocardial Infarction, Arrhythmias, and Sudden Cardiac Death: A Systematic Review and Meta-Analysis
3
The Egyptian Journal of Internal Medicine. A comparison of electrocardiographic parameters in e-cigarette users, conventional cigarette smokers, and non-smokers
4
PubMed Central. Sympathomimetic Effects of Acute E-Cigarette Use: Role of Nicotine and Non-Nicotine Constituents
5
PubMed Central. E-cigarettes and arrhythmogenesis: a comprehensive review of pre-clinical studies and their clinical implications
6
PubMed Central. E-cigarettes and their lone constituents induce cardiac arrhythmia and conduction defects in mice
7
PubMed Central. In vitro and in vivo cardiac toxicity of flavored electronic nicotine delivery systems
8
PubMed. Oxidative stress mediates cardiac electrophysiological injury in inhalation exposure to flavored vaping products
9
PubMed Central. Influence of Cooling Agents on the Arrhythmogenic and Autonomic Effects of Electronic Cigarettes in an in vivo Model
10
PubMed Central. Increased vulnerability to atrial and ventricular arrhythmias caused by different types of inhaled tobacco or marijuana products
11
PubMed Central. Influence of e-cigarettes and their constituents on cardiac rhythm and arrhythmias
12
PubMed Central. Vaping Associated Cardiac Arrest at School in a Teenager with Anomalous Left Coronary Artery
13
PubMed Central. Role of cannabis in cardiovascular disorders